Printing telegraph apparatus



P 1, 1942- w. J. ZENNER 2,294,436

PRINTING TELEGRAPH APPARATUS Original Filed Dec. 51, 1936 v ill/1 WIIIIIIII 4 INVENTOR WALT E R J. ZENNER ATTORNEY Patented Sept. 1, 1942 2,294,436 PRINTING TELEGRAPH-APPARATUS Walter J. Zenner, Des Plaines, lll., assignor to Teletype Corporation, Chicago, "111., a corporation of Delaware Original application December 31, 1936, Serial No.

118,525, now Patent No. 2,228,716, dated January 14, 1941. Divided and this application January 11, 1941, Serial No. 374,071

9' Claims.

This invention relates to printing telegraph apparatus, and more particularly to selector mechanisms for controlling the operation of such apparatus. 7

This application is a division of application Serial No. 118,525, filed December 31, 1936-, by W. J. Zenner.

' An object of this invention is to provide a selector mechanism of the assisted armature type in which the armature assisting lever is at all times free to engage the element by which it is operated.

Another object of this invention is to provide a selector mechanism in which the energy required to be supplied to the selector magnet is minimized.

The invention features the provision of a completely resilient and self-centering articulation between the armature assisting lever and the selector lever in a selector mechanism.

The invention also features an armature assisting lever which is in continuous engagement with its operating cam.

For a full and complete understanding of selector mechanisms of the type to which the features of this invention may be applicable, reference may be had to U. S. Patent No. 1,937,376, granted November 28, 1933, to Walter J. Zenner. in one specific application of this invention, there is provided a power driven flutter cam which positions an assisting lever periodically tcward and away from the selector magnet and through a self-centering spring connection, the assisting lever causes a selector lever to be similarly operated. An armature carried by the selector lever is accordingly presented to the selector magnet and in the event that a marking impulse is received, the magnet will retain the selector lever to properly condition the selector mechanism in response to the received signal impulse but the assisting lever will be restored by the flutter cam to its positionaway from the selector magnet creating an unbalance in the selfcentering connection between the assisting lever and selector lever. When the selector magnet is deenergized in response to the termination of the marking impulse, the armature is released and the selector lever is moved by the self-centering mechanism into proper relation with respect to the assisting lever.

For a complete understanding of the invention, reference may be had to the following detailed description, taken in connection with the accompanying drawing, in which- Fig. 1 is a plan view showing a selector mechanism in which the selector magnet controls a latch for the armature assisting lever;

Fig. 2 is a vertical sectional view taken on the line 2-2 of Fig. 1;

Fig. 3 is a fragmentary plan view showing a selector mechanism in which periodic movement of the armature assisting lever is not affected by the operation of the magnet armature; and

Fig. 4 is a vertical sectional view taken on the line 4-4 of Fig. 3.

Referring now to the drawing in which identical reference characters designate corresponding parts throughout the several views, and. particularly to Figs. 1 and 2, reference numeral 2| designates a mounting plate for a selector mechanism for printing telegraph apparatus. A selector magnet assembly indicated generally by the reference numeral 22 comprises a bracket 23 to which is secured, by means of screws 24, a magnet core 26. Core 26 has two arms, each of which supports a winding 21 which is adapted to be connected to a telegraph line. At their outer ends the arms of core 26 terminate in pole faces 28.'

Bracket 23 supports opposed pivot screws 29, which in turn pivotally support a bell crank lever 3| one arm of which carries selector magnet armature 32, and the other arm of which terminates in a latching shoulder 33. Magnet bracket 23 has a depending boss 34 which, in addition to mounting the lower pivot screw 29 for the latching bell crank 31, extends through a close fitting aperture in mounting plate 2| and establishes a center of rotation for selector magnet bracket 23. The bracket 23 is provided with arcuate apertures 36, the arcs of which have their centers on the axis of boss 34, and through which extend clamping screws 31 to threadedly engage mounting plate 2]. At a point remotefrom boss 34 bracket 23 threadedly supports the shank of an adjusting screw 38 which is provided with head 39, and,'spaced therefrom along the shank, flange 4|. A stud 42 is rigidly secured to mounting plate 2|, and extends upwardly into the space between head 39 and flange 4!. Screw head 39 may be provided with the usual slot (not shown) for cooperation with a screw driver, and there may be provided in the periphery of the head, sockets 43 into which a pin may be inserted for rotation of screw 38 in the manner in which capstans are rotated. The sockets 43 permit rotation of screw 38 by suitable implement when the installation of the selector mechanism is such as to prevent access to the slotted head by a screw 5 driver.

It will be apparent that when screw 38 is rotated, it can undergo no axial movement, due to the confining action of head 39 and flange 4| upon stud 42. Since screw 38 threadedly engages bracket 23, the latter must move toward or away from stud 42 as the screw is rotated, and in so moving it pivots upon boss 34 and varies the air gap between pole faces 28 and armature 32.

An armature assisting lever 44 pivoted by means of screws 46 on bracket 41 secured to mounting plate 2| is disposed in operative alignment with an armature assisting cam 48 included in a selector cam assembly, indicated generally by the reference numeral 49, mounted on power driven shaft extending through mounting plate 2|. Cam assembly 49 is arranged to be driven from shaft 5| through discs 52 fixed to shaft 5|, resilient discs 53 in frictional engagement with discs 52, and discs 54 fixed to cam assembly 49 and in frictional engagement with discs 53. Discs 52, 53, and 54 constitute friction clutch assemblies. Selector cam assembly 49 includes a stop arin 56 which is arranged to be arrested and released for rotation alternatively under the control of a stop gate 51 included in a stop gate assembly 58. Stop gate assembly 58 has as its foundation a plate 59 pivoted below a plate 6| by means of pivot screw 62 carried by plate 6| which is secured by screws 63 to posts (not shown) mounted on mounting plate 2 I. An arm 64 mounted on pivot screw 62 above plate 6| has extending therethrough the shank of a knurled-headed screw 69 which threadedly engages stop gate mounting plate 59. Plate 59 may be adjusted rotationally about pivot screw 62 and may be clamped in any desired position of adjustment by drawing plate 59 and arm 64 into clamping engagement with plate 6| by means of screw 96.

Stop gate 51 is pivotally mounted on post 61 carried by plate 59, has a portion disposed in the path of stop arm 56, and may be latched in that position by shouldered latch lever 69. Lever 66 is pivotally mounted on the under side of plate 59 and is urged by spring 69 into latching engagement with stop gate 51. Latch lever 68 is rocked against the resistance of compression spring 69 to lift its shoulder out of latching engagement with the stop gate by a plunger pin II in the operating path of which is disposed one arm of a bell crank 72, the other arm of which engages latch lever 68. A plunger operating screw I3 carried by extension 14 of armature lever arm 44 in alignment with plunger pin II shifts the pin to rock bell crank I2, which, in turn, rocks latch lever 68 and effects the release of the stop gate when the armature lever is in its extreme clockwise position. Plunger pin II is retracted by spring 69 and permits latch lever 68 to latch stop gate 51 when armature assisting lever 44 is in its extreme counterclockwise position.

Armature assisting lever 44 is shown in Fig. 1 in its extreme counterclockwise position. In moving into this position, it rocks bell crank 3| into its extreme clockwise position through engagement with yieldable compression spring 16 associated with bell crank 3|. Armature 32 is thus brought into engagement with pole face 28. Armature assisting lever 44 has a lug 11 so disposed in relation to shoulder 33 of lever 3| that when levers 44 and 3| are in their counterclockwise and clockwise positions respectively, shoulder 33 is in blocking relation to lug I1. Cam 48 periodically rocks lever 44 into its counterclockwise position, and if magnet 21 is energized and holds armature 32 in opposition to biasing spring 18 of bell crank 3|, shoulder 33 will hold armature assisting lever 44 in opposition to its biasing spring I9 after cam 48 has rotated sufiiciently to remove an apex from engagement with lever 44 and to present a nadir portion thereto. If mag net 21 is not energized, spring I8 withdraws lever 3| from latching engagement with armature assisting lever 44, and spring 19 rocks lever 44 to its clockwise position when a nadir portion of the cam is presented to lever 44.

A selector lever 8| is pivotally supported by screws 92 carried by a mounting bracket 83 secured to mounting plate 2|. A tension spring 84 has one end connected to select-or lever GI and the other end secured to extension 83 of annature assisting lever arm 44. Extension 86 also carries an abutment screw 97 which is adjustable with respect thereto, and the head of which abuts selector lever 8| intermediate its ends. At its free end, which is the right-hand end as viewed in Fig. 1, selector lever 8| is provided with spaced depending arms 88, by means of which the setting of selector elements of a sword and T'-lever selector assembly is controlled.

The sword and T-lever assembly is designated generally by the reference numeral 9|, and comprises a plurality of thin, fiat selector fingers, or

sword levers 92, and an equal number of T-levers 93 individually aligned with the sword levers 92. Sword levers 92 are individually supported by spacer plates 94 which also separate the T-levers 93 and which are mounted on studs 96. Each of the sword levers 92 has at its left-hand end, as viewed in Fig, 1, a disc-like portion 91 which is fitted into a correspondingly shaped aperture in a sword operating bell crank lever 93 pivotally mounted on pivot pin 99. Each of the bell crank levers 98 is arranged to be rocked counterclockwise by one of a plurality of cam projection I9| carried by the cam assembly 49 in helical arrangement. Adjacent to the disc-like portion 91 each sword lever 92 is provided with oppositely extending arms I92 which terminate in abutments I93.

T-levers 93 are rotatably mounted upon pivot pin I94 carried by mounting plate 2| and each of the levers 93 is provided with an arm I06 which terminates in a disc-like portion I91. T-levers 93 are intended to be articulated, by means of the disc-like portions I91, to code bars, code discs, or other permutation code elements (not shown) as disclosed in Patent No. 1,745,633 granted February 4, 1930 to S. Morton et al.

Pivot pin 99, in addition to supporting sword lever operating bell cranks 99, also pivotally supports a locking bell crank lever I99 which has one arm I99 terminating in a cam follower portion which engages a locking cam III, included in cam assembly 49, and has another arm 2 terminating in a locking blade I I3 adjacent to which selector lever 8| is provided with a locking lug II4.

Selector lever BI is adapted to be rocked, in a manner which will be described later, through an arc suificient to bring one or the other of its arms 88 into the path of one or the other of abutments I63 of sword levers 92 as the sword levers are reciprocated leftwardly by associated bell cranks 98, and such angular movement of selector lever 8| is sufricient to bring locking lug 4 from one side to the other of locking blade II 3, Continued reciprocation of a sword lever, after one of its abutments I03 has engaged one of the depending arms 88 of selector lever 8|, causes the sword lever to move angularly about the center of its disc-like ortion to bring its free end into engagement with its associated T-levers 93 at either side of the pivotal mounting I04 thereof. The angular movement of sword levers 92 is limited by stop pins II6 carried by mounting plate 2|. Sword lever bell cranks 98 and locking bell crank I08 are biased clockwise and counterclockwise respectively, by tension spring (not shown).

The selector mechanism shown in Figs. 1 and 2 is adapted to be controlled by permutation code signals comprising marking and spacing impulses in various combinations received by the selector magnet winding 21 from the telegraph line to which it is connected. When the selector mechanism is not operating and is responding to a stop impulse, which is of marking nature and is manifested by energized condition of selector magnet 21, armature 32 is held to pole face 28, latch lever 3| engages lug 11 of armature assisting lever 44 and holds that lever in its extreme counterclockwise position out of engagement with cam 48, which, in the rest condition, presents a nadir portion to lever 44, and abutment screw 13 is drawn away from plunger pin 1|, which, being retracted, causes stop gate 51 to be latched to hold cam assembly 49 motionless. When a code signal combination is received, the first impulse thereof is the start impulse which results in deenergization of the selector magnet and permits spring 18 to rotate latch lever 3| counterclockwise, thus releasing lever 44 which rocks into engagement with cam 48 and depresses plunger pin 1|, whereby stop gate 51 is released from latch lever 68. Cam assembly 49 rotates through one revolution during the reception of a code combination, and, in rotating, cam 48 rocks armature assisting lever 44 counterclockwise, cam III unlocks selector lever 8|, these operations occurring periodically, and cam projections |0| rock sword lever bell cranks 98 counterclockwise successively. All of these operations occur in timed relation to the reception of code signal impulses. If the selector magnet is energized at the instant armature cam 48 actuates armature assisting lever 44 to bring armature 32 into engagement with pole face 28 and lever 3| into latching engagement with lug 11, the armature will be held and latch lever 3| will hold armature assisting lever 44 in its extreme counterclockwise position in opposition to tension spring 19, whereby abutment screw 81 will be drawn away from selector lever 8|. Upon the unlocking of selector lever 8|, tension spring 84 will cause the lever to be rotated to its extreme counterclockwise position, whereby one of the arms 88 will be presented to an abutment I03 of a particular sword lever 92 to effect the setting of the sword lever in accordance with the energized condition of the selector magnet. When the selector magnet is deenergized at a time that armature 34 is brought into engagement with pole face 28 by armature assisting cam 48, the armature will not be held, latch lever 3| will not hold lever 44, which will return to its extreme clockwise position, and the selector lever, when unlocked, will be positioned in accordance with the deenergized condition of the selector magnet.

A code signal combination concludes with a stop impulse which is represented by the energized condition of the selector magnet. The arrocked by cam I40.

mature is thus held, and armature assisting lever 44 is retained in its extreme counterclockwise position by latch lever 3|, whereby plunger pin 1| is permitted to be retracted by spring 69, and stop gate 51 is locked. It follows from this that cam assembly 49 is arrested at the conclusion of one revolution and, with a nadir portion presented to latched lever 44, awaits release by the start impulse of the next code signal combination.

The selector mechanism hereinbefore described has the advantageous feature that winding 21 is required to carry only sufficient energizing current to cause armature 32 to be held in opposition to tension spring 18. None of the stored energy of armature assisting lever restoration spring 19 is operative upon armature 32, but is instead resisted by latching shoulder 33 which has positive blocking relation to latching lug 11 until the selector magnet releases its armature. The use of low transmitting potentials is thus made possible.

Referring now to Figs. 4 and 5, it will be noted that a selector mounting plate I2| supports a selector magnet assembly I22 and brackets I23 and I24 on which selector lever I26 and armature assisting lever I21 are respectively pivotally mounted by means of pivot screws I28 and I29, respectively. Armature assisting lever I21 is urged into extreme clockwise position by tension spring I 3| land is periodically rocked counterclockwise by armature assisting cam I32 included in selector earn assembly I33 carried by powerdriven shaft I34. The armature of the selector magnet is designated I36 and is mounted directly on selector lever I26, which has, at its free end, locking lug I31 similar to that employed on selector lever 8| (Fig. 1) with which there cooperates locking bell crank lever I38 which is biased counterclockwise by spring I35, and is periodically Since selector lever I26 carries the selector magnet armature I36, the tripping of the stop gate for the selector cam assembly I33 in response to a start impulse must be under the control of that lever. Accordingly, lever I26 is provided with an arm I39 having abutment screw MI in operative alignment with stop gate latch tripping plunger pin I42 of adjustable stop gate assembly I43, a fragment only of which is shown in Fig. 4, but which may be similar to the stop gate mechanism shown in Figs. 1 and 2.

The interconnection between selector lever I26 and armature assisting lever I 21 is shown in detail in Fig. 4 by reference to which it will be observed tlrat selector lever I26 is provided with spaced depending arms I44 in alignment with which are depending arms I46 of armature assisting lever I21 spaced apart a greater distance than are the arms I44. The arms I41of selector lever I26 are apertured to receive shouldered pins I41, which are urged in opposite directions by compression spring I48 to force their outer ends into abutting relation with the inner surfaces of arms I46. With the arrangement shown in Figs. 3 and 4, selector lever I26 tends to be centered with respect to armature assisting lever I21, and if the latter is moved (angularly, an unbalance is created in the combination of pins I41 and spring I48 which causes the selector lever I26 to be moved in a direction to eliminate the unbalance when it is unlocked by locking bell crank I38. It will be observed that the interconnection between armature assisting lever I21 and selector lever I26 is resilient or permissive in both directions, as contrasted with the interconnection shown in Figs. 1 and 2, comprising a tension spring and Ian abutment SlCI'GW, the combination of which afiords a permissive or resilient interconnection in one direction, and a positive interconnection in the other direction.

In the operation of a selector mechanism, as disclosed in Fig. 3, it will be presumed that the energizing current of the selector magnet {produces enough magnetic attraction to hold selector lever I26 in opposition to a condition of unbalance in the spring interconnection between selector lever and the armature assisting lever, but which is insufficient to attract the selector lever from its extreme clockwise to extreme counterclockwise position. Due to the periodic rocking of armature assisting lever I21 counterclockwise by cam I32, an unbalance, tending to rotate selector lever I26 counterclockwise, will be generated in the interconnecting pins I4! and spring I48, and when locking bell crank I38 is actuated by cam I40 to unlock selector lever I26, the latter will be rotated to bring armature I36 into engagement with the pole face of the selector magnet I22. If the magnet is then energized, the selector lever I26 will be held in its extreme counterclockwise position after the armature assisting lever I27 has returned to its extreme clockwise position due to escapement of its cam follower portion from an apex of cam I32, and 'a selective condition corresponding to a marking signal is thus established, whereupon locking bell crank cam I40 permits locking bell crank I38 to lock lever I26.

If instead of being energized at the time the armature assisting lever I21 is rotated counterclockwise, the selector magnet should be deenergized, in response to a spacing signal, the selector lever I26 will not be held and will return to its extreme clockwise position when the armature assisting lever returns to its extreme clockwise position, whereupon the selector lever may be locked in that position, which corresponds to a spacing signal condition of the selector magnet.

With the arrangement shown in Figs. 3 and 4, the selector magnet armature is not associated with the armature assisting lever, but is associated with the selector lever. The selector magnet is not called upon to actuate selector lever I26, nor to hold it in opposition to its relatively strong restoring spring I3I, but is only required to hold it in opposition to a relatively weak unbalance in the centering spring mechanism when the armature lever returns to its extreme clockwise position. The restoring spring for the armature assisting lever may thus be as heavy as desired. Furthermore, the armature assisting lever is never held out of engagement with the armature cam, as it may be in the structure shown in Fig. 1, by latch lever I3I, but is instead continuously responsive in its movements to the contour of the armature cam.

Although particular embodiments of the invention have been shown and described herein, it is to be understood that the invention is not to be interpreted as being limited to the specific details shown and described, but is capable of modification and rearrangement within the scope of the appended claims.

What is claimed is:

1. In combination, an electromagnet, an armature therefor, a spring biased element presentable into either of two positions, means for presenting said element into one of said positions in opposition to the spring bias, means controlled by said element for presenting said armature to said electromagnet, and means for delaying the efiectiveness of the last-mentioned means.

2. In a selector mechanism, an electromagnet, an armature therefor, a selection controlling lever to which said armature is attached, a power driven cam, a lever having a portion continuously in engagement with said cam, and yielding interconnections between said levers causing the first-mentioned lever to tend to follow the movements of thesecond-mentioned lever.

3. In combination, an electromagnet, an armature therefor, a lever to which said armature is attached, a second lever having a portion overlying the first, means for rocking the second lever periodically, and opposed spring-urged pins carried by the first-mentioned lever in engagement with the overlying portion of the second lever for biasing the first mentioned lever in accordance with the movements of the second lever.

4. In an electro-responsive device, an electromagnet, a pivoted lever carrying an armature for said electromagnet and having opposeddepending arms intermediate the ends, opposed shouldered pins supported in said arms, a compression spring engaging said shouldered pins and urging them outwardly, a second lever having a portion overlying the first-mentioned lever and having arms outside and in alignment with the first-mentioned arms depending from said overlying portion, the outer ends of said pins abutting the depending arms of said overlying portion, means for periodically rocking the second lever, and means operated in timed relation to the last-mentioned means for controlling the armature supporting lever.

5. In a selector mechanism, an electromagnet, a selection controlling lever conditioned electromagnetically by said electromagnet, an assisting lever operable to position said selection controlling lever within the control of said electromagnet, a biasing spring, and a power driven cam for actuating said assisting lever periodically, said assisting lever being maintained in continuous engagement with said cam by said biasing spring.

6. In combination, an electromagnet, a lever controlled in accordance with the condition of said electromagnet, an assisting lever operable periodically to position said first-mentioned lever within the influence of said electromagnet, and a self-centering connection between said levers 'Whereby said first-mentioned lever tends to fol low the positionment of said assisting lever.

'7. In a selector mechanism, an electromagnet, an armature therefor, a selection controlling lever to which said armature is attached, an as sisting lever, a power driven cam with which said assisting lever is in continuous engagement, said cam operating said assisting lever periodically, and a self-centering connection between said controlling lever and said assisting lever whereby said last-mentioned lever is effective to position said armature into its attracted position periodically.

8. In a selector mechanism, an electromagnet, a selection conditioning member controlled thereby, a spring biased element movable toward or away from said electromagnet, means for moving said element toward said electromagnet in opposition to the spring bias, means controlled by said element for presenting said selection conditioning member to said electromagnet, and

means for delaying the operation of said lasttromagnet, a self-centering connection between mentioned means. said assisting lever and. said controlling lever 9. In a selector mechanism, an electromagnet, whereby the latter tends to follow the movements an armature therefor, a selection controlling of said assisting lever, and a cam controlled lever to which said armature is attached, an as- 5 means for timing the following movement of sisting lever, a, cam with which said assisting said levers.

lever is in continuous engagement and which WALTER J. ZENNER. moves said lever toward and away from said elec- 

